Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * main.c
4 : * Stub main() routine for the postgres executable.
5 : *
6 : * This does some essential startup tasks for any incarnation of postgres
7 : * (postmaster, standalone backend, standalone bootstrap process, or a
8 : * separately exec'd child of a postmaster) and then dispatches to the
9 : * proper FooMain() routine for the incarnation.
10 : *
11 : *
12 : * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
13 : * Portions Copyright (c) 1994, Regents of the University of California
14 : *
15 : *
16 : * IDENTIFICATION
17 : * src/backend/main/main.c
18 : *
19 : *-------------------------------------------------------------------------
20 : */
21 : #include "postgres.h"
22 :
23 : #include <unistd.h>
24 :
25 : #if defined(__NetBSD__)
26 : #include <sys/param.h>
27 : #endif
28 :
29 : #if defined(_M_AMD64) && _MSC_VER == 1800
30 : #include <math.h>
31 : #include <versionhelpers.h>
32 : #endif
33 :
34 : #include "bootstrap/bootstrap.h"
35 : #include "common/username.h"
36 : #include "port/atomics.h"
37 : #include "postmaster/postmaster.h"
38 : #include "storage/s_lock.h"
39 : #include "storage/spin.h"
40 : #include "tcop/tcopprot.h"
41 : #include "utils/help_config.h"
42 : #include "utils/memutils.h"
43 : #include "utils/pg_locale.h"
44 : #include "utils/ps_status.h"
45 :
46 :
47 : const char *progname;
48 :
49 :
50 : static void startup_hacks(const char *progname);
51 : static void init_locale(const char *categoryname, int category, const char *locale);
52 : static void help(const char *progname);
53 : static void check_root(const char *progname);
54 :
55 :
56 : /*
57 : * Any Postgres server process begins execution here.
58 : */
59 : int
60 3078 : main(int argc, char *argv[])
61 : {
62 3078 : bool do_check_root = true;
63 :
64 : /*
65 : * If supported on the current platform, set up a handler to be called if
66 : * the backend/postmaster crashes with a fatal signal or exception.
67 : */
68 : #if defined(WIN32) && defined(HAVE_MINIDUMP_TYPE)
69 : pgwin32_install_crashdump_handler();
70 : #endif
71 :
72 3078 : progname = get_progname(argv[0]);
73 :
74 : /*
75 : * Platform-specific startup hacks
76 : */
77 3078 : startup_hacks(progname);
78 :
79 : /*
80 : * Remember the physical location of the initially given argv[] array for
81 : * possible use by ps display. On some platforms, the argv[] storage must
82 : * be overwritten in order to set the process title for ps. In such cases
83 : * save_ps_display_args makes and returns a new copy of the argv[] array.
84 : *
85 : * save_ps_display_args may also move the environment strings to make
86 : * extra room. Therefore this should be done as early as possible during
87 : * startup, to avoid entanglements with code that might save a getenv()
88 : * result pointer.
89 : */
90 3078 : argv = save_ps_display_args(argc, argv);
91 :
92 : /*
93 : * Fire up essential subsystems: error and memory management
94 : *
95 : * Code after this point is allowed to use elog/ereport, though
96 : * localization of messages may not work right away, and messages won't go
97 : * anywhere but stderr until GUC settings get loaded.
98 : */
99 3078 : MemoryContextInit();
100 :
101 : /*
102 : * Set up locale information
103 : */
104 3078 : set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("postgres"));
105 :
106 : /*
107 : * In the postmaster, absorb the environment values for LC_COLLATE and
108 : * LC_CTYPE. Individual backends will change these later to settings
109 : * taken from pg_database, but the postmaster cannot do that. If we leave
110 : * these set to "C" then message localization might not work well in the
111 : * postmaster.
112 : */
113 3078 : init_locale("LC_COLLATE", LC_COLLATE, "");
114 3078 : init_locale("LC_CTYPE", LC_CTYPE, "");
115 :
116 : /*
117 : * LC_MESSAGES will get set later during GUC option processing, but we set
118 : * it here to allow startup error messages to be localized.
119 : */
120 : #ifdef LC_MESSAGES
121 3078 : init_locale("LC_MESSAGES", LC_MESSAGES, "");
122 : #endif
123 :
124 : /*
125 : * We keep these set to "C" always, except transiently in pg_locale.c; see
126 : * that file for explanations.
127 : */
128 3078 : init_locale("LC_MONETARY", LC_MONETARY, "C");
129 3078 : init_locale("LC_NUMERIC", LC_NUMERIC, "C");
130 3078 : init_locale("LC_TIME", LC_TIME, "C");
131 :
132 : /*
133 : * Now that we have absorbed as much as we wish to from the locale
134 : * environment, remove any LC_ALL setting, so that the environment
135 : * variables installed by pg_perm_setlocale have force.
136 : */
137 3078 : unsetenv("LC_ALL");
138 :
139 3078 : check_strxfrm_bug();
140 :
141 : /*
142 : * Catch standard options before doing much else, in particular before we
143 : * insist on not being root.
144 : */
145 3078 : if (argc > 1)
146 : {
147 3078 : if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
148 : {
149 0 : help(progname);
150 0 : exit(0);
151 : }
152 3078 : if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
153 : {
154 894 : fputs(PG_BACKEND_VERSIONSTR, stdout);
155 894 : exit(0);
156 : }
157 :
158 : /*
159 : * In addition to the above, we allow "--describe-config" and "-C var"
160 : * to be called by root. This is reasonably safe since these are
161 : * read-only activities. The -C case is important because pg_ctl may
162 : * try to invoke it while still holding administrator privileges on
163 : * Windows. Note that while -C can normally be in any argv position,
164 : * if you want to bypass the root check you must put it first. This
165 : * reduces the risk that we might misinterpret some other mode's -C
166 : * switch as being the postmaster/postgres one.
167 : */
168 2184 : if (strcmp(argv[1], "--describe-config") == 0)
169 0 : do_check_root = false;
170 2184 : else if (argc > 2 && strcmp(argv[1], "-C") == 0)
171 0 : do_check_root = false;
172 : }
173 :
174 : /*
175 : * Make sure we are not running as root, unless it's safe for the selected
176 : * option.
177 : */
178 2184 : if (do_check_root)
179 2184 : check_root(progname);
180 :
181 : /*
182 : * Dispatch to one of various subprograms depending on first argument.
183 : */
184 :
185 : #ifdef EXEC_BACKEND
186 : if (argc > 1 && strncmp(argv[1], "--fork", 6) == 0)
187 : SubPostmasterMain(argc, argv); /* does not return */
188 : #endif
189 :
190 : #ifdef WIN32
191 :
192 : /*
193 : * Start our win32 signal implementation
194 : *
195 : * SubPostmasterMain() will do this for itself, but the remaining modes
196 : * need it here
197 : */
198 : pgwin32_signal_initialize();
199 : #endif
200 :
201 2184 : if (argc > 1 && strcmp(argv[1], "--boot") == 0)
202 1074 : AuxiliaryProcessMain(argc, argv); /* does not return */
203 1110 : else if (argc > 1 && strcmp(argv[1], "--describe-config") == 0)
204 0 : GucInfoMain(); /* does not return */
205 1110 : else if (argc > 1 && strcmp(argv[1], "--single") == 0)
206 380 : PostgresMain(argc, argv,
207 : NULL, /* no dbname */
208 380 : strdup(get_user_name_or_exit(progname))); /* does not return */
209 : else
210 730 : PostmasterMain(argc, argv); /* does not return */
211 : abort(); /* should not get here */
212 : }
213 :
214 :
215 :
216 : /*
217 : * Place platform-specific startup hacks here. This is the right
218 : * place to put code that must be executed early in the launch of any new
219 : * server process. Note that this code will NOT be executed when a backend
220 : * or sub-bootstrap process is forked, unless we are in a fork/exec
221 : * environment (ie EXEC_BACKEND is defined).
222 : *
223 : * XXX The need for code here is proof that the platform in question
224 : * is too brain-dead to provide a standard C execution environment
225 : * without help. Avoid adding more here, if you can.
226 : */
227 : static void
228 3078 : startup_hacks(const char *progname)
229 : {
230 : /*
231 : * Windows-specific execution environment hacking.
232 : */
233 : #ifdef WIN32
234 : {
235 : WSADATA wsaData;
236 : int err;
237 :
238 : /* Make output streams unbuffered by default */
239 : setvbuf(stdout, NULL, _IONBF, 0);
240 : setvbuf(stderr, NULL, _IONBF, 0);
241 :
242 : /* Prepare Winsock */
243 : err = WSAStartup(MAKEWORD(2, 2), &wsaData);
244 : if (err != 0)
245 : {
246 : write_stderr("%s: WSAStartup failed: %d\n",
247 : progname, err);
248 : exit(1);
249 : }
250 :
251 : /* In case of general protection fault, don't show GUI popup box */
252 : SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);
253 :
254 : #if defined(_M_AMD64) && _MSC_VER == 1800
255 :
256 : /*----------
257 : * Avoid crashing in certain floating-point operations if we were
258 : * compiled for x64 with MS Visual Studio 2013 and are running on
259 : * Windows prior to 7/2008R2 SP1 on an AVX2-capable CPU.
260 : *
261 : * Ref: https://connect.microsoft.com/VisualStudio/feedback/details/811093/visual-studio-2013-rtm-c-x64-code-generation-bug-for-avx2-instructions
262 : *----------
263 : */
264 : if (!IsWindows7SP1OrGreater())
265 : {
266 : _set_FMA3_enable(0);
267 : }
268 : #endif /* defined(_M_AMD64) && _MSC_VER == 1800 */
269 :
270 : }
271 : #endif /* WIN32 */
272 :
273 : /*
274 : * Initialize dummy_spinlock, in case we are on a platform where we have
275 : * to use the fallback implementation of pg_memory_barrier().
276 : */
277 3078 : SpinLockInit(&dummy_spinlock);
278 3078 : }
279 :
280 :
281 : /*
282 : * Make the initial permanent setting for a locale category. If that fails,
283 : * perhaps due to LC_foo=invalid in the environment, use locale C. If even
284 : * that fails, perhaps due to out-of-memory, the entire startup fails with it.
285 : * When this returns, we are guaranteed to have a setting for the given
286 : * category's environment variable.
287 : */
288 : static void
289 18468 : init_locale(const char *categoryname, int category, const char *locale)
290 : {
291 18468 : if (pg_perm_setlocale(category, locale) == NULL &&
292 0 : pg_perm_setlocale(category, "C") == NULL)
293 0 : elog(FATAL, "could not adopt \"%s\" locale nor C locale for %s",
294 : locale, categoryname);
295 18468 : }
296 :
297 :
298 :
299 : /*
300 : * Help display should match the options accepted by PostmasterMain()
301 : * and PostgresMain().
302 : *
303 : * XXX On Windows, non-ASCII localizations of these messages only display
304 : * correctly if the console output code page covers the necessary characters.
305 : * Messages emitted in write_console() do not exhibit this problem.
306 : */
307 : static void
308 0 : help(const char *progname)
309 : {
310 0 : printf(_("%s is the PostgreSQL server.\n\n"), progname);
311 0 : printf(_("Usage:\n %s [OPTION]...\n\n"), progname);
312 0 : printf(_("Options:\n"));
313 0 : printf(_(" -B NBUFFERS number of shared buffers\n"));
314 0 : printf(_(" -c NAME=VALUE set run-time parameter\n"));
315 0 : printf(_(" -C NAME print value of run-time parameter, then exit\n"));
316 0 : printf(_(" -d 1-5 debugging level\n"));
317 0 : printf(_(" -D DATADIR database directory\n"));
318 0 : printf(_(" -e use European date input format (DMY)\n"));
319 0 : printf(_(" -F turn fsync off\n"));
320 0 : printf(_(" -h HOSTNAME host name or IP address to listen on\n"));
321 0 : printf(_(" -i enable TCP/IP connections\n"));
322 0 : printf(_(" -k DIRECTORY Unix-domain socket location\n"));
323 : #ifdef USE_SSL
324 0 : printf(_(" -l enable SSL connections\n"));
325 : #endif
326 0 : printf(_(" -N MAX-CONNECT maximum number of allowed connections\n"));
327 0 : printf(_(" -o OPTIONS pass \"OPTIONS\" to each server process (obsolete)\n"));
328 0 : printf(_(" -p PORT port number to listen on\n"));
329 0 : printf(_(" -s show statistics after each query\n"));
330 0 : printf(_(" -S WORK-MEM set amount of memory for sorts (in kB)\n"));
331 0 : printf(_(" -V, --version output version information, then exit\n"));
332 0 : printf(_(" --NAME=VALUE set run-time parameter\n"));
333 0 : printf(_(" --describe-config describe configuration parameters, then exit\n"));
334 0 : printf(_(" -?, --help show this help, then exit\n"));
335 :
336 0 : printf(_("\nDeveloper options:\n"));
337 0 : printf(_(" -f s|i|n|m|h forbid use of some plan types\n"));
338 0 : printf(_(" -n do not reinitialize shared memory after abnormal exit\n"));
339 0 : printf(_(" -O allow system table structure changes\n"));
340 0 : printf(_(" -P disable system indexes\n"));
341 0 : printf(_(" -t pa|pl|ex show timings after each query\n"));
342 0 : printf(_(" -T send SIGSTOP to all backend processes if one dies\n"));
343 0 : printf(_(" -W NUM wait NUM seconds to allow attach from a debugger\n"));
344 :
345 0 : printf(_("\nOptions for single-user mode:\n"));
346 0 : printf(_(" --single selects single-user mode (must be first argument)\n"));
347 0 : printf(_(" DBNAME database name (defaults to user name)\n"));
348 0 : printf(_(" -d 0-5 override debugging level\n"));
349 0 : printf(_(" -E echo statement before execution\n"));
350 0 : printf(_(" -j do not use newline as interactive query delimiter\n"));
351 0 : printf(_(" -r FILENAME send stdout and stderr to given file\n"));
352 :
353 0 : printf(_("\nOptions for bootstrapping mode:\n"));
354 0 : printf(_(" --boot selects bootstrapping mode (must be first argument)\n"));
355 0 : printf(_(" DBNAME database name (mandatory argument in bootstrapping mode)\n"));
356 0 : printf(_(" -r FILENAME send stdout and stderr to given file\n"));
357 0 : printf(_(" -x NUM internal use\n"));
358 :
359 0 : printf(_("\nPlease read the documentation for the complete list of run-time\n"
360 : "configuration settings and how to set them on the command line or in\n"
361 : "the configuration file.\n\n"
362 : "Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
363 0 : printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
364 0 : }
365 :
366 :
367 :
368 : static void
369 2184 : check_root(const char *progname)
370 : {
371 : #ifndef WIN32
372 2184 : if (geteuid() == 0)
373 : {
374 0 : write_stderr("\"root\" execution of the PostgreSQL server is not permitted.\n"
375 : "The server must be started under an unprivileged user ID to prevent\n"
376 : "possible system security compromise. See the documentation for\n"
377 : "more information on how to properly start the server.\n");
378 0 : exit(1);
379 : }
380 :
381 : /*
382 : * Also make sure that real and effective uids are the same. Executing as
383 : * a setuid program from a root shell is a security hole, since on many
384 : * platforms a nefarious subroutine could setuid back to root if real uid
385 : * is root. (Since nobody actually uses postgres as a setuid program,
386 : * trying to actively fix this situation seems more trouble than it's
387 : * worth; we'll just expend the effort to check for it.)
388 : */
389 2184 : if (getuid() != geteuid())
390 : {
391 0 : write_stderr("%s: real and effective user IDs must match\n",
392 : progname);
393 0 : exit(1);
394 : }
395 : #else /* WIN32 */
396 : if (pgwin32_is_admin())
397 : {
398 : write_stderr("Execution of PostgreSQL by a user with administrative permissions is not\n"
399 : "permitted.\n"
400 : "The server must be started under an unprivileged user ID to prevent\n"
401 : "possible system security compromises. See the documentation for\n"
402 : "more information on how to properly start the server.\n");
403 : exit(1);
404 : }
405 : #endif /* WIN32 */
406 2184 : }
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